PBC Cart and Checkout BO GLUEAPI and Tutorials SEO Update

[james-hooper-spryker]

PR Description

Changed the mate description for the following pages as an SEO update;

• manage in the back office > define global thresholds
• manage in the back office > manage threshold settings
• manage in the back office > manage thresholds the back office
• manage using glue API > glue api check out purchases
• manage using glue API > glue api checkout workflow
• manage using glue API > glue api retrieve customer carts
• manage using glue API > glue api manage shared company user carts
• manage using glue API > glue api retrieve cart permission groups
• manage using glue API > glue api share company user carts
• tutorials and how tos > add additional countries to checkout
• tutorials and how tos > define if carts are deleted after placing an order
• tutorials and how tos > enable guest checkout in the b2b demo shop
• tutorials and how tos > handling carts with a big number of items
• cart and checkout

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Checklist

• I agree with the Code Contribution License Agreement in CONTRIBUTING.md